 ;; be swapped (regardless of where they appear in the string).
 (defn swap-letter
   [text fr to]
-  text)
+  (-> text
+   (str/replace fr ".")
+   (str/replace to fr)
+   (str/replace "." to)))
+
 
 
 ;; swap letter d with letter a

;; dabc.
(defn rotate-right
  [text fr]
  text)


;; rotate right 4 steps

;; right one time, plus a number of times equal to that index, plus
;; one additional time if the index was at least 4.

;; (rotate-based-on "ecabd" "d") => "decab"
;; (rotate-based-on "abdec" "b") => "ecabd"

;; rotate based on position of letter a
(defn parse-rotate-based-on
  "Apply cmd to text. Return text as is if cmd isn't this cmd"
